JP2011503090A - Use of sulfuryl fluoride as a germination inhibitor - Google Patents

Abstract

  The present invention relates to suppression of germination of potato tubers by using sulfuryl fluoride.

Description

This application claims priority to US Provisional Application No. 61 / 002,298, filed Nov. 8, 2007. The entire disclosure is hereby incorporated by reference.

  The present invention relates to the use of sulfuryl fluoride to inhibit germination in tubers, particularly potatoes.

  It is well known in the art to treat tubers such as potatoes with various chemicals having germination inhibiting properties. CIPC (chlorpropham, chlorprophame; chloro-IPC, IRPAC name isopropyl 3-chlorocarbanilate; isopropyl 3-chlorophenylcarbamate; Chemical Abstracts name 1-methylethyl (3-chlorophenyl) carbamate EEC number 202-925 7) has traditionally been used for this purpose for over 40 years.

  Potato tubers are often treated with chemical germination inhibitors during storage and may be subject to another treatment with germination inhibitors before being packaged for shipping to retail stores. Without chemical germination inhibitors, maximum shelf life is greatly reduced due to loss of dormancy and early germination. Thus, virtually all potatoes that are stored for medium to long periods are treated with chemical germination inhibitors.

  Potatoes are frequently subject to pushes, cuts and / or wear as they are dug. These trauma to potatoes often cause damage during shipping, storage, etc. A process known as corking occurs naturally, and many of these traumas are healed. However, whenever potatoes are stored (this storage is associated with most potatoes harvested in a given year), if healing occurs slowly, damage can cause a significant loss of potatoes . Early treatment with some germination inhibitors such as CIPC may delay the corkification process, thus contributing to the loss of potato due to injury.

  The main registered germination inhibitors for use in potato are CIPC, maleic hydrazide (MH), and dimethylnaphthalene (DMN) and diisopropyl-naphthalene (DIPN). Combining two chemicals (CIPC and DIPN) appears to be more effective at lower concentrations than either of the two chemicals alone. Simultaneous application of CIPC and DIPN improves results over separate application of either germination inhibitor.

  For example, treating potatoes with CIPC to prevent or delay germination in potatoes is relatively common in the potato storage industry. Untreated potatoes begin to germinate after one month of storage, even when stored at cold temperatures, for example, generally between about 36-52 ° F. Storing for 6-10 months or more is common for potato storage. Therefore, when chemical substances such as CIPC are not treated, the stored potatoes are entangled with buds, and the entire stored potatoes may be economically wasted. Early treatment with CIPC may be advantageous for germination control purposes, but since CIPC tends to delay corking, application of CIPC is typically postponed until after corking occurs, and spoilage and Causes damage acceleration.

  CIPC is typically applied in one or more applications to the stored tubers using thermal spray techniques, sprays and powders. Conventional thermal spraying applies CIPC in a hot air stream at 550-1000 ° F. or on a hot surface to produce a CIPC aerosol. CIPC aerosol circulates between the potatoes stacked in the potato storage with the use of a blower. Preferably, potato stacks are softer than soft when processed with CIPC aerosol, as softened potato stacks can be substantially pressurized, thereby impeding aerosol distribution. Rather it is swollen. However, CIPC residual levels will typically decrease over time due to biodegradation, emissions and losses caused by the atmosphere. Additional applications may be required to extend the effective germination inhibition capacity of CIPC.

  CIPC is used in significant amounts throughout the world and has the ability to inhibit germination on stored tubers with a chemical ability to limit cell division. Along with stringent storage management strategies, increasing ratios, multiple applications, adding substituted naphthalenes chemistry have been implemented to help reduce germination in potatoes treated with CIPC.

  CIPC is known to be one of the three pesticides found in the highest concentrations in the average American diet (Gartrell et al., “Pesticides Selected Elements, and Other Chemicals in Adult Total. Diet Samples, October 1980-March 1982 ", J. Assoc. Off. Anal. Chem., 69: 146-159, 1986), accounting for more than 90% of all synthetic chemical residues found in potatoes in the United States (Gunderson, J. “FDA Total Diet Study, April 1982-April 1984, Dietary Industries of Pesticides, Selecte. Elements, and Other Chemicals ", Assoc.Off.Anal.Chem, 71:. 1200~1209 page, 1988). Due to its persistence in the environment and potato organization, its toxicity concerns are being reviewed by the Environmental Protection Agency. CIPC is a derivative of ethyl urethane, a well-known carcinogen, and it is not known if it will be converted back to its parent compound when inoculated (Mondy et al., “Effect of Storage. Time, Temperature, and Cooking On Isopropyl N- (3-chlorophenol) Carbamate Levels in Potatoes, "J. Agric. Food Chem., 40: 197-199, 1992). Since CIPC is in a weak position, the potato industry is looking for alternative drugs for germination control.

  The present invention provides an effective anti-sprouting treatment protocol that does not use CIPC and / or does not praise the use of CIPC. More particularly, the present invention relates to a method of inhibiting potato tuber germination comprising contacting the potato tuber with an amount of sulfuryl fluoride effective to inhibit germination. In addition to using alone, sulfuryl fluoride can be used in combination with any other germination inhibitor (s).

  Sulfuryl fluoride is a non-flammable, non-corrosive gaseous material that boils at about -52 ° C. It is used as a fumigant for the control of nematodes, bacteria, molds and insects, especially for the control of structural and post-harvest pests, such as Isoptera, Coleoptera, Lepidoptera and Cockroaches The Sulfuryl fluoride is toxic to plants but has little effect on weed or crop seed germination.

  As used herein, the term “tuber tube” encompasses “potato tubers,” which refers to the underground storage organ of a potato plant (Solanum tuberosum). Potato tubers are modified stems that contain shoots that can germinate and form new potato plants. The term “(potato) tuber” generally refers to both tubers and potato tubers. Preferred potatoes include Russet Burbank, Ranger Russet, Umatilla Russet, Shepody, Norkotah Russet, Yukon Gold, Norchip, Gem Russet, Atlantic R

  The expression “effective to inhibit germination” means that (a) the number and / or weight of stems (buds) grown from a defined number of (potato) tubers contacted with sulfuryl fluoride according to the present invention Less than the number and / or weight of stems grown from the same number of control (potato) tubers (in the same cultivar as the treated (potato) tubers) not contacted with the inhibitor, and / or (b) according to the present invention Growing from the same number of control (potato) tubers (treated (potato) tubers) with the same average rate of growth of stems grown from a specified number of (potato) tubers contacted with sulfuryl fluoride Means less than the average rate of growth of stems grown from (variety). Such suppression is always possible compared to the control. As will be appreciated by those skilled in the art, the concept of inhibition is profound when the control tuber exhibits suppressed activity in tubers contacted with sulfuryl fluoride. Another preferred suppression criterion is a comparison of the total amount of “dormant + up to 3 mm buds” tubers, eg 50 days after harvest, compared to untreated controls. Whatever criterion is used, the preferred amount of suppression is less than 1%, 1%, 3%, greater than 3%, 5%, 8%, 10%, 20%, 30%, etc. to 100% Is included.

  In general, the present invention includes any application of sulfuryl fluoride to tubers, particularly after application to potato plants in the field before harvesting potatoes and / or after harvesting potatoes, Application before storage and / or application after storage of potatoes. In a preferred embodiment, sulfuryl fluoride is applied as a gas to harvested potatoes. Sulfuryl fluoride can also be applied for the first time or subsequent to harvesting tubers (potatoes) and storing them for a sufficient period of time when the wounds and cuts heal, ie, corking occurs. In another aspect of the invention, sulfuryl fluoride is applied to inhibit germination during the potato shipment and sale process.

  In accordance with the foregoing, the present invention provides a method for inhibiting potato tuber germination, each method comprising contacting the potato tuber with an effective amount of sulfuryl fluoride to inhibit potato tuber germination. Including. Typically, sulfuryl fluoride is applied to a large number of harvested potato tubers simultaneously or substantially simultaneously. In practicing the method of the invention, sulfuryl fluoride is applied after harvesting potato tubers but typically by the start of germination. In some embodiments of the methods of the present invention, an effective amount of sulfuryl fluoride is a dosage much less than 1 mg (parts per million) per kg of potato tubers, for example, dosages up to 100 ppm, 500 ppm or more. Enough to provide. Preferred amounts include 0.01, 0.05, 0.1, 0.2, 0.3, 0.5, 1, 2, 3, 5, 8, 10, 15, 20, 25, 30, 35. , 40, 50, 60 ppm, and the like.

  The present invention provides a method for inhibiting germination of stored tubers, in particular potatoes, by applying a first germination inhibiting chemical to the stored potato and then applying a second germination inhibiting chemical. And at least one of the germination-inhibiting chemicals is sulfuryl fluoride which forms part of the present invention, and “second germination-inhibiting chemicals” include CIPC, MCPP, and DMN or DIPN, particularly 2, 6 diisopropylnaphthalene may be included. Multiple substances can be applied together, or the time that elapses between the first chemical application and the second chemical application can be from a few hours to several months. The second chemical substance is generally applied during the period when the effect of the germination inhibiting feature of the first chemical substance becomes weaker.

  In accordance with the foregoing, in one aspect, the present invention provides a method of treating (potato) tubers, each method comprising contacting the (potato) tuber with sulfuryl fluoride. Preferably, the amount of sulfuryl fluoride is an amount effective to inhibit germination of (potato) tubers. However, this is not essential. For example, when sulfuryl fluoride is used with another germination inhibitor, sulfuryl fluoride can be used in an amount less than that effective to inhibit germination of potato tubers. Preferably, of course, the total amount of germination inhibitor (ie, the amount of sulfuryl fluoride and any additional germination inhibitor (s)) is effective to inhibit germination of potato tubers.

  In the present invention, sulfuryl fluoride includes 1 including products containing phosphite, hydrogen peroxide (dioxide), sodium chlorite, chlorine dioxide, thiobendazole, azoxystrobin, fludioxonil, and mancozeb. It can also be used with one or more antibacterial and / or disease-suppressing active agents. In a preferred embodiment of the invention, sulfuryl fluoride is applied after harvesting potato tubers but typically by the start of germination. Thus, in some embodiments of the methods of the invention, sulfuryl fluoride is applied to the tubers within 1, 2, 3, 4, 5, 6, 7 or 8 weeks after harvesting the tubers. Typically, sulfuryl fluoride is applied before the natural dormancy period of the harvested potato tubers is over, ie before the buds on the potato tubers begin to germinate. Preferably, sulfuryl fluoride is applied as close as practicable to the natural dormancy period. The duration of the natural dormancy period is known to those skilled in the art and varies among potato cultivars and depends on factors such as the physiology and conditions of the tubers at harvest and the storage temperature. For example, depending on temperature and potato cultivar, the natural dormant period estimate (in days) would be about 70-140 days at a temperature of 45-48 ° F.

  When potatoes are subjected to reconditioning, sulfuryl fluoride is typically applied at the beginning of the reconditioning period. Thus, in some embodiments of the invention, the sulfuryl fluoride is applied 1, 2, 3, 4 or 5 weeks before processing the potato tubers to make french fries or potato chips. In carrying out the method of the present invention, sulfuryl fluoride can be applied to potato tubers more than once (eg, at least twice) during storage.

  Typically, but not as a requirement, sulfuryl fluoride is applied to a number of harvested potato tubers simultaneously or substantially simultaneously. Potatoes can generally be stored in mass storage designed to store, for example, about 1 ton to about 50,000 tonnes, more usually about 5,000 to 25,000 tonnes. For process efficiency, it is preferred to use sulfuryl fluoride in enclosed land that can accommodate tubers such as at least 1 ton of potato tubers. The reservoir is designed to accurately manage ventilation through a pile (which may be about 25 feet deep) in addition to temperature and relative humidity. Temperature is controlled by cooling and / or ventilation with outside air through a cell deck that also increases humidity. For example, sulfuryl fluoride can be applied in a storage ventilation system that circulates air from bottom to top during potato stacking. The reservoir is generally closed tightly after processing and air can be circulated internally between the stacks for several hours after the application of sulfuryl fluoride. Other types of enclosed land can be used, preferably enclosed land with humidity and temperature management devices.

  The amount of sulfuryl fluoride applied to the potato tubers is preferably an amount effective to inhibit tuber germination. Inhibition of germination may vary in the present invention, from minimal but some to complete inhibition, including all differences between them.

  The amount of sulfuryl fluoride effective to inhibit potato tuber germination depends on the potato cultivar being treated. In some embodiments of the methods of the invention, sulfuryl fluoride provides a dosage from any measurable amount, such as 0.001 ppm, for example, 50, 100, 200, 500, 1000 ppm, etc. Apply to potato tubers in sufficient quantity. In another embodiment, the concentration of sulfuryl fluoride in contact with the tubers is from about 1 gram per cubic meter of enclosed land in which the tubers are present to less than 16 grams per cubic meter. In another embodiment, the concentration of sulfuryl fluoride is about 2-15 grams per cubic meter. In another embodiment, the concentration of sulfuryl fluoride is about 2-14 grams per cubic meter. In another embodiment, the concentration of sulfuryl fluoride is about 2-12 grams per cubic meter. Usually, the contact time is longer than 2 hours. In another embodiment of the invention, the contact time is longer than 4 hours. In another embodiment of the invention, the contact time is longer than 6 hours. In another embodiment of the invention, the contact time is longer than 8 hours. In general, the time does not exceed one week. In another embodiment of the invention, the time does not exceed 5 days. In another embodiment of the invention, the time does not exceed 3 days. In another embodiment of the invention, the time does not exceed 2 days.

  The methods of the present invention include Rustset Burbank, Ranger Russet, Umatilla Russet, Shepody, Norkot Russset, Yukon Gold, Norchip, Gem Russet, Atlantic, Chipet, Nand Applicable to cultivars.

These examples are provided to illustrate some embodiments of the present invention. The invention is not limited to these illustrated embodiments.
[Example 1]

Russet and Red potatoes were purchased from organic retailers and used for this study. These potatoes were treated in a Styrofoam ™ fumigation disinfection chamber in four treatments (0 grams-hour / cubic meter [gh / m ³ ], 500 g-h / m ³ , 1000 g-h / m ³ and 1500 g-h / m ³ ). The exposure time was 12 hours at 50 percent relative humidity and an ambient temperature of about 25 ° C. Details of the processing are listed in Table 1. After the exposure time, sulfuryl fluoride was released and the treated potatoes were observed for their physical properties and germination (Tables 2-8).

[Example 2]

A second test was performed using stored Russet Burbank potatoes. These potatoes were exposed to ^three treatments (0 g-h / m ³ , 300 g-h / m ³ , and 500 g-h / m ³ ) in a Styrofoam ™ fumigation chamber. The exposure time was 12 hours at 50 percent relative humidity and an ambient temperature of about 25 ° C. The treatment was repeated 3 times. Approximately 10 lbs of potato was used for each repeat. Details of the processing are listed in Table 9. After the exposure time, sulfuryl fluoride was released and the treated potatoes were observed for their physical properties and germination (Tables 10 and 11).

As shown in Tables 10 and 11, these treatments stopped the buds from growing.
[Example 3]

A third test was performed using stored organic Russet potatoes. These potatoes were treated in four treatments (0 g-h / m ³ , 50 g-h / m ³ , 100 g-h / m ³ , 150 g-h / m ³ and 200 g-h / m ³ in a Styrofoam ™ fumigation chamber. ³ ) exposed. The exposure time was 12 hours at 50 percent relative humidity and an ambient temperature of about 25 ° C. The treatment was repeated 3 times. Approximately 1 lb of potato was used for each repeat. After exposure time and appropriate dosage accumulation, sulfuryl fluoride was released and the treated potatoes were observed for their physical properties and germination (Tables 12, 13 and 14).

As presented in Table 13, germination inhibition was dose dependent. The 50 g-h / m ³ and 100 g-h / m ³ treatments had significant germination growth after 21 days of treatment compared to the 150 g-h / m ³ and 200 gh / m ³ treatments. The 150 g-h / m ³ treatment had a slight germination growth after 7 days of treatment, however, the shoots did not grow any more during the observation after 21 days of treatment. The peel test showed that none of the treatments used in this test produced black spots as observed in previous tests. The 200 g-h / m ³ treatment resulted in the best germination inhibition without any phytotoxic effect even after 31 days.

Claims (7)

  A method for inhibiting germination in the tuber after harvesting the tuber and also placing the tuber on the enclosed land, comprising contacting the tuber with sulfuryl fluoride for a period exceeding 2 hours, The method wherein the concentration of the sulfuryl fluoride in the enclosed land is from about 1 gram per cubic meter of enclosed land to less than 16 grams per cubic meter of enclosed land.   The method of claim 1, wherein the concentration of the sulfuryl fluoride is from about 2 to about 15 grams per cubic meter.   The method of claim 1, wherein the concentration of the sulfuryl fluoride is about 2 to about 14 grams per cubic meter.   The method of claim 1, wherein the concentration of the sulfuryl fluoride is about 2 to about 12 grams per cubic meter.   The method of claim 1, wherein the time exceeds about 4 hours.   The method of claim 1, wherein the time exceeds about 6 hours.   The method of claim 1, wherein the time exceeds about 8 hours.